Secondary battery and method of fabricating the same

Abstract

The present invention relates to a secondary battery and a method of fabricating the same. In a secondary battery according to an embodiment of the invention, holding members for holding a molded resin member are formed on a cap plate of a bare cell, which prevents the molded resin member from being distorted or detached from the cap plate of the bare cell when battery parts, such as a protection circuit board and a secondary protection element, are coupled to the bare cell by the molded resin member.

1. A secondary battery, comprising:
 an electrode assembly having a positive electrode plate, a negative electrode plate, and a separator interposed between the positive electrode and the negative electrode wound in sequence; 
 a can housing the electrode assembly; 
 a bare cell including a cap assembly having a cap plate sealing an upper open portion of the can and an electrode terminal inserted into a through hole formed in the cap plate with a gasket interposed therebetween and at least one projecting portion integrally formed in the electrode terminal to extend transversely outward from the electrode terminal; 
 a resin member molded to fill between the cap plate of the bare cell and a protection circuit board and to fill between the cap plate and the projecting portion; 
 the protection circuit board coupled to and being held spaced-apart from the bare cell by the molded resin member; and 
 holding protrusions projecting from one surface of the cap plate, holding portions extending transversely from distal sections of the holding protrusions and engaging the molded resin member between the cap plate and the protection circuit board, and recesses disposed on an opposite surface of the cap plate and each of the recesses geometrically corresponding to each of the holding protrusions. 
 
     
     
       2. The secondary battery as claimed in  claim 1 ,
 wherein the holding portions are formed at a top of the holding protrusions so as to extend in parallel to the cap plate. 
 
     
     
       3. The secondary battery as claimed in  claim 2 , wherein the holding protrusions being formed in T shapes in sectional view. 
     
     
       4. The secondary battery as claimed in  claim 1 ,
 wherein the holding protrusions are formed at both sides of an upper surface of the cap plate. 
 
     
     
       5. The secondary battery as claimed in  claim 1 ,
 wherein the cap plate and the holding protrusions are formed of aluminum or aluminum alloy. 
 
     
     
       6. A secondary battery, comprising:
 an electrode assembly having a positive electrode plate, a negative electrode plate, and a separator insulating the positive electrode plate from the negative electrode plate wound in sequence; 
 a can housing the electrode assembly; 
 a bare cell including a cap assembly which has a cap plate comprised of a head bearing a projecting portion comprised of at least one step portion, said cap plate sealing an upper open portion of the can and an electrode terminal which is inserted into a through hole formed in the cap plate with a gasket interposed therebetween; 
 a resin member molded to fill between the cap plate of the bare cell and a protection circuit board; 
 the protection circuit board coupled to an upper part of the bare cell by the molded resin member; and 
 at least one projecting portion integrally formed in the electrode terminal to extend radially outwardly from the electrode terminal and engage a portion of the resin member disposed between the gasket and an underside of the projecting portion. 
 
     
     
       7. The secondary battery as claimed in  claim 6 , wherein said electrode terminal comprises said projecting portion holding the molded resin member formed on the cap plate of the bare cell. 
     
     
       8. The secondary battery as claimed in  claim 7 ,
 wherein holding protrusions are formed on the cap plate and have T shapes in sectional view. 
 
     
     
       9. The secondary battery as claimed in  claim 8 ,
 wherein the holding protrusions are formed at both sides of an upper surface of the cap plate. 
 
     
     
       10. The secondary battery as claimed in  claim 8 ,
 wherein the cap plate and the holding protrusions are formed of aluminum or aluminum alloy. 
 
     
     
       11. The secondary battery as claimed in  claim 6 ,
 wherein the electrode terminal includes a body and a head which is formed at a top of the body so as to extend in a widthwise direction, and the projecting portion is formed on a lower surface of the head. 
 
     
     
       12. The secondary battery as claimed in  claim 11 ,
 wherein the width of the head of the electrode terminal is longer than the width of the gasket.